The present invention relates generally to systems for the selective distribution of fluid. More specifically, the present invention relates to air distribution systems for motor vehicles and a rotary air distribution chamber that achieves the selective distribution of air in such a system.
There are numerous applications in which it is desirable to distribute a fluid in a selective manner, i.e., distribute the fluid or portions of the fluid to various distinct locations. For example, motor vehicles, such as automobiles, planes, and other transportation and utility vehicles, normally include a ventilation system for distributing air to the passenger compartment. These systems frequently include a variety of vent locations, such a floor vents, instrument panel vents, defrost vents, rear passenger vents and others. Furthermore, most systems allow the user to select an operating mode that distributes air to a single desired vent or a combination of several vents.
To accomplish this selective distribution of air, the system must include a distribution chamber that is capable of directing air flow to the appropriate vent or vents, as selected by the user. Some distribution chambers take the form of a box having a plurality of doors, with each door serving as an opening to a particular pathway that ultimately terminates in a vent. These box like structures are frequently bulky and, due to the use of doors, difficult to manufacture and repair. Another design for these distribution chambers includes a cylindrical housing having multiple inner barrels, such as that disclosed in U.S. Pat. No. 6,113,483 to Schambre et al for a VARIABLE MODE AIR DISTRIBUTION SYSTEM. This design is still relatively complex in that it requires multiple interior barrels and involute surfaces attached or integrally formed on the barrels. Furthermore, the presence of involute surfaces results in areas within the distribution chamber that may collect dead air when the barrels are not aligned in a manner that creates an opening. This may decrease the efficiency of the distribution chamber. Also, this design does not include any restriction on the rotation of the barrels other than the actuator or controller. This may result in inadvertent movement of the barrels, which may alter the flow of air through the chamber.
The present invention provides a rotary distribution chamber for a fluid distribution system that comprises a nested pair of chambers. At least one surface of each chamber defines multiple sections with stepped diameters, and each section has at least one opening. When the opening of a section on one chamber is aligned with the opening of the adjacent section on the other chamber, fluid from within the rotary distribution chamber is able to escape through the aligned openings for travel down connected pathways. The rotary distribution chamber further includes a shaft that allows axial and rotational movement of the inner chamber, an actuator that controls such movement, and a series of seals between the two chambers at the spaces between the stepped diameters. The structure of the rotary distribution chamber and its operational features provide an uninterrupted chamber with direct access to the openings corresponding to selected vents in a vehicle air distribution system. Thus, there is no dead space within the rotary distribution chamber, which allows for unimpeded flow of air through the distribution chamber into the selected vents. Furthermore, the seal, in addition to the ability of the inner chamber to move along its axis, restricts the rotation of the inner barrel, thereby preventing inadvertent changes in air flow.